Mining
A Framework for Success
Mining infrastructure investment is costly but crucial
By Rindi White
M

ining has been going on for a long time, from flint pebbles extracted in France and Britain about 10,000 years ago to Egyptian copper mines roughly 5,000 years ago. The Encyclopedia Britannica pegs the oldest mine in the world to be a 40,000-year-old ochre mine in Swaziland.

But no matter what substance is being mined, all mines rely on infrastructure to provide access to the mineral deposit and ways to get it out of the ground.

Today’s mines are much more advanced than those early ochre, flint, and copper mines. From roads wide enough to accommodate heavy duty equipment to remote vehicle operations, mines today are operate on the cutting edge of technology.

Usibelli Coal Mine
A mining site with large excavation equipment
Workers Vital

A mine might be able to operate without roads or power, but it couldn’t operate without people. And although some Alaska mines are close to existing communities, all need to have onsite facilities to accommodate the needs of employees, from bathrooms and break areas to camps serving hundreds of people.

Fort Knox, a gold mine operated by Kinross, employs about 730 people. It’s a surface mine, one of very few cold-weather, sub-arctic heap leach mines operating in the world. It’s located 26 miles from Fairbanks, so workers can commute to the mine.

Contrast that with Coeur Alaska’s Kensington Mine, about 45 miles north-northwest of Juneau on the Lynn Canal, which employs about 400 people year-round but houses about 250 people at a time at the camp throughout the year. Fort Knox utilizes existing infrastructure—namely area roads—to transport its workers to the mine each day, while those who work at the Kensington mine arrive there via a twice-daily boat service.

Mark Kiessling, Kensington Mine’s general manager, says Coeur Mining uses the Juneau highway system to bus employees to a leased port facility at Yankee Cove, then a contracted boat transportation service takes workers to the mine. Many of the administrative employees work four days on, three days off, he says, and many commute via the boat daily. But most workers spend their two-week shift at the mine.

The 255-bed camp also offers an onsite medical clinic and gym facility, as well as a helipad and helicopter support. Summer means exploration, and the contracted helicopter service assists with drilling and exploration activities.

Healy, about 100 miles from Fairbanks, is a town whose infrastructure exists almost exclusively because of mining—coal seams visible to those passing through the Healy valley were documented by 1908, but it was another ten years before a railway came through that could transport the coal to market, often to supply the railroad with a reliable source of coal for its steam engines.

Alex Legrismith, an engineer for Usibelli Coal Mine, flies a drone over an active mining area to obtain real-time insight.

Usibelli Coal Mine

Alex Legrismith, an engineer for Usibelli Coal Mine, flies a drone over an active mining area to obtain real-time insight.

Usibelli Coal Mine

Alex Legrismith, an engineer for Usibelli Coal Mine flying a drone
A worker washes down wheels on a large dump truck used in Kensington Mine. The mine’s tunnels are 15 feet wide and 17 feet tall to accommodate the large equipment.

Coeur Alaska

A worker washes down wheels on a large dump truck used in Kensington Mine. The mine’s tunnels are 15 feet wide and 17 feet tall to accommodate the large equipment.

Coeur Alaska

A worker washes down wheels on a large dump truck

Healy River Coal Company opened a mine in 1919 and shipped the first load of coal to Fairbanks in the winter, a celebrated event.

Emil Usibelli, founder of Usibelli Mine, began as a Healy River Coal employee in 1936, working at the mining operation nearby in Suntrana and, seven years later, opened a mine east of Suntrana. He and his partner, Tad Sanford, established the first Usibelli camp there in 1949. The town of Healy, its one-room school, coal-fired power plant, and other infrastructure primarily existed because of Usibelli; it supported other mines in the area and the railroad for many years, according to an article, “Healy History,” by Beverly Hall Mitchell.

“We’re preparing ourselves for future possibilities—one is the concept of automation, allowing underground equipment to be operated from the surface.”
Mark Kiessling, General Manager, Coeur Mining

Usibelli Vice President of External Affairs Lorali Simon said in an April 1 breakfast presentation to the Alaska Resource Development Council that Usibelli remains Alaska’s only operating coal mine, employing 100 year-round workers. When the Parks Highway was built to Fairbanks in 1971, the community’s economy diversified. Fourteen years later, the town, formerly owned by the railroad, was auctioned off into private ownership.

Transportation Crucial

While Healy may be a relatively extreme example of infrastructure created to assist a mine, with a railroad and entire town created around Usibelli and other nearby mines, transportation infrastructure will always be a necessary part of mine development. Most mines have miles of roads both on the surface and—in the case of underground mines—below. Usibelli Coal Mine operates and maintains about 25 miles of road throughout its holdings to facilitate its mining and reclamation processes.

Fort Knox has a 5.6-mile access road, plus about 30 miles of active road within the mine holdings, along which more than thirty enormous CAT haul trucks rumble daily, as well as three shovels and two giant CAT loaders. Expansion, like the Gil deposit at Fort Knox, means building more roads, says Anna Atchison, external affairs manager for Kinross. Although roads are extended all the time, building a new, long road is infrequent she says—only twice in twenty-five years has Kinross built new roads for its surface mining activities.

Coeur Alaska operates Kensington Mine’s dock facility at Slate Creek Cove.

Coeur Alaska

Coeur Alaska operates Kensington Mine’s dock facility at Slate Creek Cove.

Coeur Alaska

Coeur Alaska operates Kensington Mine’s dock facility at Slate Creek Cove
A train is loaded with ultra-low sulfur coal from Usibelli Coal Mine’s tipple facility for transportation to power plants in Interior Alaska.

Usibelli Coal Mine

A train is loaded with ultra-low sulfur coal from Usibelli Coal Mine’s tipple facility for transportation to power plants in Interior Alaska.

Usibelli Coal Mine

A train is loaded with ultra-low sulfur coal from Usibelli Coal Mine's tipple facility

Kensington, with a 5.7-mile access road, has about 13 miles of roads on the surface and about 30 miles of tunnels within its underground development. Building a mining access tunnel is a significant undertaking, Kiessling says. Tunnels are blasted 15 feet wide and 17 feet tall, large enough to allow Kensington to use underground trucks to haul out ore and diesel trucks to carry workers and supplies into the mine.

A Power-hungry Operation

Mines require power—lots of it.

Usibelli uses a Bucyrus-Erie 1300W walking dragline, which the company says is the largest land-mobile machine in Alaska. When the electric dragline was connected to the Golden Valley Electrical Association system in 1977, GVEA’s power production could not keep up with the draw from the machine, which draws 6 megawatts when digging and regenerates 2 megawatts when the bucket is extended. Every time the 4-million-pound dragline dug into the dirt, removing the sandstone and clay lying atop the coal seams, lights in houses would flicker. To combat this, Usibelli built a 40-ton flywheel system and installed it parallel to the drag line to feed power back into the electrical system and even out the drain on power.

“We’re always looking for ways to continue to feed our mill and extend the mine life. What we have permitted is about eighty years of coal production at our current levels, but that larger number of coal reserves—those are in our lease boundary.”
Lorali Simon, Vice President of External Affairs, Usibelli Coal Mine

Kiessling says the Kensington Mine has significant power needs. It takes a significant amount of power to operate a ball mill and crusher and provide power for electric drills and pumps to move water within the mine. Treating water is a power-intensive action, and so is operating the camp, particularly in winter when more heat is needed.

The mine site is too distant from Juneau to tap into an existing power source and, even if it were close enough, there isn’t sufficient power supply to provide permanent firm power. As a result, the company produces its own power, he says. For many years it used a diesel plant with seven generators. But that system was dated and the mine, ready to expand, needed more power. Coeur in 2019 finished a significant power plant upgrade, with four high-efficiency diesel generators. The new plant decreased fuel consumption by 25 percent and improved emissions by 85 percent and has room to expand, he says. Typically, only two generators are needed in the summer and a third in winter. And more improvements are in the works.

“We’re looking at other technology as well, including hydropower and energy storage banks, to store any excess power that we could generate,” he says.

Water: Byproduct, Essential Tool, and Closely Monitored Waste Product

Adequate water is vital to a successful mine operation. Most mines require water to help separate materials either through centrifugal force or a chemical separation process, and some use water to transport ore and waste in a slurry from one area to the next. Water is also needed to suppress dust at mine sites and for workers’ personal use. In many cases, finding water is the easy part—moving it to mine efficiently can be a larger problem.

“Mother nature is the only source of added water through rain and snowmelt,” Atchison says. “Water is not hard to find, as the site acts as an 8-mile drainage system that collects either in the ground or in the ponds.”

Atchison says Fort Knox requires about 7,000 gallons a minute, which circulates from the mine’s collection ponds to the mill and back. Additional water generated at the mine is treated with reverse osmosis before discharge.

Kiessling says Kensington, located in the middle of a temperate rainforest, does not lack for water.

“We intercept subsurface water as we mine. We reuse water through our processes, either through drilling or milling. Before we’re done with it and ready to discharge it, we treat it,” he says, giving a simplified overview.

Kensington operates two process water treatment plants, one that treats the excess water produced and a second that treats water at its tailing treatment facility. At both places, excess water is treated to drinking water standards before discharge. Between the two plants, Kiessling says Kensington treats about 3.2 million gallons of wastewater a day. Comparatively, the City and Borough of Juneau treats around 5 million gallons of wastewater a day at three treatment facilities.

Keeping It Together: Connectivity

Communication between the mine site and the administration buildings, wherever they are located, is important for mining. Roughly a century ago, Palmer residents knew of an accident in the mines nearby because a train whistle would blow in town, where most of the miners’ wives lived. The whistle still blows today, blowing at 8 a.m., Noon, and 5 p.m.—a nod to the region’s mining history.

Communication today is markedly different, and much more personal. Kiessling says Kensington has onsite cell towers to bring wireless and internet connections to the mine. The mine has two internet providers: one for the workers and the other for camp needs. It might seem like duplication, but it’s really a backup supply to make sure the mine is always connected. Within the mine itself are two communication networks, he says. One is an IT network with a fiber backbone and the second is a radio network that runs other operations.

A miner operates a jumbo drill at Kensington Mine.

Coeur Alaska

A miner operates a jumbo drill at Kensington Mine.
A miner operates a jumbo drill at Kensington Mine.

Coeur Alaska

“We can push data from the underground environment to the surface really rapidly, and from our facility to our office in Juneau or to corporate headquarters in Chicago,” he says. “It has required a lot of thought about how we handle our network.”

That thought and planning is becoming ever more important, he says.

“We’re preparing ourselves for future possibilities—one is the concept of automation, allowing underground equipment to be operated from the surface,” he says.

The freshwater facilities at Fort Knox—thousands of gallons of water are processed each minute at the Fort Knox mine.

Greg Martin | Kinross

The freshwater facilities at Fort Knox—thousands of gallons of water are processed each minute at the Fort Knox mine.
The freshwater facilities at Fort Knox—thousands of gallons of water are processed each minute at the Fort Knox mine.

Greg Martin | Kinross

That’s already happening to some extent. Kensington has been using automated loaders underground to move recently blasted rock away from a blast site in preparation for loading onto a truck. The automated loaders, controlled remotely by operators on the surface, do not interact with vehicles that have drivers in them, he says. Automation is one way Kensington has maintained a high safety rating.

Coeur Alaska recently installed a new, more efficient four turbine power plant at its Kensington Mine.

Coeur Alaska

Coeur Alaska recently installed a new, more efficient four turbine power plant at its Kensington Mine.

Coeur Alaska

Coeur Alaska recently installed a new, more efficient four turbine power plant at its Kensington Mine.
“We can push data from the underground environment to the surface really rapidly, and from our facility to Kensington in Juneau or to corporate in Chicago. It has required a lot of thought about how we handle our network.”
Mark Kiessling, General Manager, Coeur Mining

“It allows us to mine in areas right after blasting, without people in there,” he says. Blasting—which happens twice a day—creates a lot of dust, which must be removed before workers can safely enter these areas hour, he explains. Driverless vehicles allow the company to capitalize on time that was previously lost.

Estimating the cost of infrastructure within a mine’s yearly budgeting process is never an easy task, but Kiessling estimated infrastructure, including underground mine development, averages about 15 percent of Coeur Alaska’s total operating and capital budget. The Kensington Mine was permitted in 2005 with an estimated mine life of ten years and a projected yield of 1,400 tons of ore daily. But Coeur Alaska has been mining for more than ten years now and produced 125,000 ounces of gold last year. Kiessling says the revised mine life is now through 2023, although Coeur Alaska is working on some advanced exploration projects that the company hopes will further extend Kensington’s operational lifespan.

Likewise, Fort Knox is currently permitted until 2024, Atchison says. That mine was also given an estimated life of ten years, and the estimated yield was 4 million ounces of gold. The mine has been operating for twenty-four years—and it poured its 8 millionth in 2019.

“We’re always looking for ways to continue to feed our mill and extend the mine life,” she says.

Simon says Usibelli has enough coal reserves to supply Alaska’s coal needs for another 1,000 years. “What we have permitted is about eighty years of coal production at our current levels, but that larger number of coal reserves—those are in our lease boundary,” Simon says.

All mines are required to have a closure and reclamation plan on file with and approved by the State of Alaska.